D3.464 - Influences of Climate and Environmental Exposures on Atopic Dermatitis Persistence and Asthma Development in Early Childhood: 6-Year Follow-up of Longitudinal Study

We investigated the impact of long-term environmental exposures on the persistence of atopic dermatitis (AD) and development of allergic outcomes in early childhood.

In this prospective cohort study, 121 infants diagnosed with AD before 24 months of age in Seoul, Korea, were followed until 6 years of age. Individual long-term exposures to PM₁₀, NO₂, O₃, CO, temperature, and relative humidity were estimated using geocoded residential addresses from birth to age 6. Associations between environmental exposures and three outcomes by age 6−AD persistence, physician-diagnosed asthma, and sensitization to aeroallergens−were assessed using Cox proportional hazards regression models. Models were adjusted for sex, body mass index (BMI), and SCORing Atopic Dermatitis (SCORAD) index at enrollment.

By age 6, 33.1% of children had persistent AD and 18.2% developed asthma. AD persistence was associated with temperature [Hazard Ratio (HR) = 0.33, 95% Confidence Interval (CI): 0.12–0.95, P = 0.040], female sex (HR = 0.36, 95% CI: 0.18–0.72, P = 0.004), and baseline disease severity (HR = 1.05, 95% CI: 1.03–1.07, P < 0.001). Asthma development was linked to temperature (HR = 0.23, 95% CI: 0.05–0.99, P = 0.049), BMI at age 6 (HR = 0.65, 95% CI: 0.45–0.94, P = 0.021) and AD severity at enrollment (HR = 1.03, 95% CI: 1.00–1.07, P = 0.039). Long-term PM₁₀ exposure did not show association with either AD persistence or asthma development. No environmental factors were associated with aeroallergen sensitization.

In children with early-onset AD, long-term ambient temperature exposure is associated with both AD persistence and asthma development, while long-term exposure to air pollutants has no significant effect. Baseline AD severity is a risk factor for adverse outcomes. These findings underscore the role of climatic factors and early disease control in shaping long-term allergic trajectories.